<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div{
           /* border-left: 1px solid red;
            border-right: 1px solid blue;
            border-top: 1px solid yellow;
            border-bottom: 1px solid green;*/
            border:5px inset red;
            width: 100px;
            height: 200px;
            /*圆角 值越大越园 超过宽高一半为正圆*/
            border-radius: 200px;
        }
    </style>
</head>
<body>
<div>边框测试</div>
</body>
</html>